Hoisting apparatus with a swingable boom and tackle, in particular for the building industry



8 Shee's-Sheet 1 F. DUERST HOIS'I'ING APPARATUS WITH A SWINGABLE BOOMAND TACKLE, IN PARTICULAR FOR THE BUILDING INDUSTRY July 9, 1968.

Filed Aug. 21.1967

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HOISTING APPARATUS WITH A SWINGABLE BOOM AND TACKLE, IN PARTICULAR FORTHE BUILDING INDUSTRY Filed Aug. 21, 1967 8 Sheets-Sheet MAw July 9,1968 F. DUERST 3,391, 0

HOISTING APPARATUS WITH A SWINGABLE BOOM AND TACKLE, IN PARTICULAR FORTHE BUILDING INDUSTRY Filed Aug. 21, 1967 8 Sheets-Sheet 5 HVVE/V70/9.

FEL/A @UEPST Y #TTORA/E/ July 9, 1968 F. DUERST 3,391,906

HOISTING APPARATUS WITH A SWINGABLE BOOM AND TACKLE, IN PARTICULAR FORTHE BUILDING INDUSTRY Filed Aug. 21, 1967 8 Sheets-Sheet 4 Fig 2b head 1./%///A/ A July 9, 1968 F. DUERST 3,

HOISTING APPARATUS WITH A SWINGABLE BOOM AND TACKLE, IN PARTICULAR FORTHE BUILDING INDUSTRY Filed Aug. 21, 1967 8 Sheets-Sheet 5 y @05 A4. w

# TTO/P/VE 1/ July 9, 1968 F. DUERST 3,391,906

HOISTING APPARATUS WITH A SWINGABLE BOOM AND TACKLE, IN PARTICULAR FORTHE BUILDING INDUSTRY Filed Aug. 21, 1967 8 Sheets-Sheet 6 Fig. 401

July 9, 1968 F. DUERST 3,391,906

HOISTING APPARATUS WITH A SWINGABLE BOOM AND TACKLE, IN PARTICULAR FORTHE BUILDING INDUSTRY Filed Aug. 21, 1967 8 Sheets-$heet 7 y 9, 1968 F.DUERST 3,391,906

HOISTING APPARATUS WITH A SWINGABLE BOOM AND TACKLE, IN PARTICULAR FORTHE BUILDING INDUSTRY Filed Aug. 21, 1967 8 Sheets-Sheet 8 Fig.4b

FELIX DUE/P57 by @0 61 w United States Patent 6 Claims. c1. 2s4 142ABSTRACT OF THE DISCLOSURE Hoisting apparatus having a horizontal loadarm, detachably secured to a support. A cable drum is detachably securedto one end of the load arm. A horizontal hinge axle is secured at theother end of the load arm. A balance is mounted on the axle. The lowerend of a swingable boom is mounted on the other end of the load armwhile the upper end of the swingable axle is reinforced by a tensionmember at the load arm.

Background of the invention The invention relates to a hoistingapparatus with a swingable boom and tackle, as employed in the buildingindustry and which is used to transport materials such as boards, beams,concrete, refuse and the like in cable rope slings or in buckets fromthe upper stories of a building to the ground or vice-versa. Knownlifting devices of this type must be supported mainly outside abuilding, e.g. at the buildings frame. This is not only unsatisfactory,but requires special load bearing frames. At the same time it ispractically impossible to construct the cable rope drum or the motordrive required there-for as a fixed component part of the liftingdevice;the cable rope drum must be mounted either on the ground or within thebuilding and supported at a desired lifting level. The mounting of thecable rope drum on the ground is not only unsatisfactory but is alsodangerous, because the service personnel must remain directly under theworking area of the swingable boom. Additionally, however, the mountingof the cable rope drum within the building requires a specialreinforcement, thus making the mounting more difficult. The knownlifting devices possess an additional disadvantage in that theirswingable booms are unstable in all of their swung positions and thusrequire a satisfactory supervision in order that unforeseen swingings ofthe swingable boom should not lead to accidents.

The object of the present invention is to provide a lifting device witha swingable boom and cable rope or tackle which will obviate the abovementioned disadvantages of known constructions. To this end the liftingdevice according to the invention consists of at least one substantiallyhorizontal load arm which is detachably secured to a support, a cablerope drum detachably secured at one end of the load arm, a horizontalhinge axle secured at the other end of the load arm, a balance mountedon said axle, the lower end of the swinging axle of the swingable boombeing mounted on said other end, while the upper end portion of theswingable axle is reinforced by means of a tension member at the loadarm.

The nearly horizontal load a-rm may be guided to the desired liftingheight through a wall opening e.g. through a window of a building, sothat the cable rope drum and, when possible, its drive motor may beplaced inside the building and the support of the load arm can likewisebe anchored within the former, while the swingable boom may be disposedentirely outside the wall of the building; a scaffold frame forsupporting this swingable boom is "ice not necessary. The load arm maybe constructed as a two-part telescoping type and accordingly may beadjustable in length.

Depending on the positioning of the swinging axis of the swingable boomon a counter-balance, the load which is suspended from the downwardlydirected cable end will be stable in the normal position when theswinging axis of the swingable boom is positioned in the vertical planeof the axis of the load arm as well as in the maxi mum possible swungposition of the swingable boom relative to this normal position. Onlyafter overcoming a dead center position during the tilting of thebalance from the first into a second tilted position takes place, canthe load be moved from one of the stable position into another. It canthus be assured that the swingable boom and therewith the load suspendedtherefrom will not swing out of any given stable position independently.Additional means are provided which guide back automatically theswingable boom after it has swung out of its normal position.

An example of an embodiment of the invention is shown in theaccompanying drawing of the lifting device according to the invention.

In the drawing:

FIG. 1 is a side view of the lifting device,

FIG. 2:21 is an enlarged detail of the device of FIG. 1,

FIG. 2a2 is another enlarged detail of the device of FIG. 1,

FIG. 2b is a side view of the supporting part with the drive unit of thelifting device,

FIG. 3 is a vertical section of a detail according to FIG. 2a,

FIG. 4a1 is an enlarged detail, in plan view, of the device of FIG. 1,

FIG. 402 is an enlarged detail, in plan view, of the device shown inFIG. 2a2,

FIG. 4b is a plan view of the part shown in FIG. 2b and FIG. 5 is across-section taken on line VV of FIG. 2b.

The lifting device comprises a horizontally mounted load arm 1 which isconstructed as a two-part telescoping pipe and protrudes from a windowopening of the building frame.

At the rear end :portion of the load arm 1, which is disposed in thebuilding structure there are provided angular struts 3a, 3b; asupporting bearing 4 is secured to the vertical flanges 3a of theseangular struts. An axle 5 is mounted in the supporting bearing 4 and onthis axle there are mounted two supporting eyes 6 of an electromotor 7.This motor, swingably supported on the axle 5,

, is braced adjustably on a brace bolt 8 which is mounted on thevertical flange 3a of the angular struts, as shown in FIG. 5. A drivehousing 10 is further secured to the vertical flange 5b by means oftension bolts 9 and an independent worm gear drive is mounted in thishousing.

The drive shaft of electromotor 7 is connected with the input shaft ofthe drive by means of a drive belt 11. A brake wheel 12, which isconnected through a free wheeling device with the motor shaft, ismounted on the motor shaft. A brake band 14 is positioned over the brakewheel 12 about the flange 3b. The brake band is connected to a tensionlever 13, which is under the tension of a spring 15.

The illustrated construction of the belt drive between the motor and thedrive mechanism is particularly advantageous, because the belt ispractically shielded and thus does not constitute a source of danger forthe personnel. A cable drum 15 is coupled with the drive axle of thedrive and this drum may be removed when disassembling the liftingdevice. The hoisting cable 17 may be wound on this drum.

A bearing angle 18 is secured to the vertical flange of the strut. Asupport pipe 20 is detachably mounted on this bearing angle by means ofclamps 19. A limit support angle 21 positioned against load arm 1 may bede- 3 tachably secured to the load arm 1 by means of clamps (not shown).

A support jack consisting of a pair of downwardly diverging supportpipes 22 is secured to the limit support angle 21. This support jackwith the limit support angle 21 may be set in a desired position underthe load arm 1.

A U-shaped frame 23 is secured with its base to the end portion of theload arm 1 extending through the window opening 2. The legs of frame 23support a transverse axle 24 in a horizontal plane. A balance 25 ismounted on the axle between the frame legs. The frame 23 is provided inits base region with a base piece 26 on which is secured a buffer 27 ofelastic rubber for the counterbalance extending directly in front of thebase of the frame 25. A supporting bearing 28 is secured between the endof the balance 25 turned towards the base of the frame and thetransverse axle 24 in this balance 25, in which the lower end of thetubular shaped swinging axle 29 of the boom is mounted.

This boom is provided with upper and lower struts 30, 31, secured at theends of the swinging axle 29, the other ends of the said struts beingconnected by means of a plate yoke 32. The upper part of the swingingaxle of the boom 29 is held in a collar 33 which is supported, by

means of struts 34, at the inturned end part of the base of the frame 23of the counterbalance. A hook 35 is further provided in collar 33 onwhich is suspended one end of a chain 36 (FIG. 2:22). The other end ofthe chain is adjustable relative to a hool (not shown) at the loadarm 1. A cable sheave 37 is mounted in the forward part of the plateyoke of the boom which extends over the struts 30, 31; a further cablesheave 38 is mounted in a plate yoke 39 secured in the upper boom part29, while a third cable sheave 40 is mounted on a plate yoke 41extending downwardly from the balance 25. The cable 17 which arrivesfrom the cable drum 16 is guided through the tubular swinging axle 29 ofthe boom through and over the cable sheaves 38 and 37 whence it isfreely suspended downwardly through a guide yoke 42 downwardly.

A modification of the hoisting device may be carried out by dispensingwith the upper strut 30. For this purpose, the strut 31 is swingablymounted on a horizontal 'bolt and the swinging axle 29, and cable 17 islooped over the cable sheave 37. This is advantageous because the cablesheave 37 and thereby the loading bucket suspended from cable 17 may bebrought close to the swinging axis, whereby the swinging circle of thesuspended load will become smaller.

The described hoisting device is provided with means for automaticallystopping of the cable drive. As particularly shown in FIG. 3, the plateyoke 41 is mounted at an upper angle point on the balance 25, wherebyits own weight as well as a spring 44 of the yoke 41 tend to swingagainst the cables pull indicated by arrow a. Furthermore, a nose 45 atthe plate yoke 41 restricts the swinging of the latter under theinfluence of the cables pull against the tensioning effect of the spring44 by means of a striker at the upper part of the H-shaped balance 25.In addition the complete yoke 41 carries a switch finger 46, whichprotrudes upwardly through an aperture in the balance bar and cooperateswith a switch 47, which is mounted on the counterbalance and which isconnected by means of an electric cable 48 in the circuit of the drivemotor 7.

As long as the bucket 43 or any other load secured to cable 17 hangsfree on this cable, the pull of the cable has the effect of closing theswitch finger 46 of the switch 47; as soon, however, as the load reachesthe ground or any other support so that the cable is released the spring44 of the yoke 41 moves the switch finger 46 thereof out of contact withthe switch 47 so that motor 7 is stopped. Similar security means areprovided in the plate yoke 32. A two-armed angular member 42 is linkedwith yoke 32 and the cable 17 is guided through the guide opening of thelatter. A spring 49 tends to pull the striker element 42 downwardly, sothat a switch finger 50 of this angular member maintains closed a switch51, connected to the cable 48, in closed position.

Should the bucket 43 or the load suspended on cable 17 be lifted so highthat it impinges against the yoke 42, then this latter will swingupwardly against the action of the spring 49 whereby the switch fingerof the switch 51 will be lifted, thus automatically disconnecting themotor drive.

Two or more lugs 52 are provided in collar 33 for inserting pins 53, inorder to secure the axle in a desired swinging position. Lateral stopvanes cooperating with said pins are secured to the swinging axle.Furthermore, a transverse rod with upwardly angled end portions issecured to the struts 34 of the boom. A spring 56 may be hung on theseend portions and this spring may be looped about the strut 31 and willthus hold the boom in a swun position determined by vane 54 and pins 53.

The above described hoisting device is used in the following manner; inorder to fill the bucket 43, it is lowered to the ground so that theboom 29, 30, 31, assumes its normal position shown in FIGS. 1, Qal, 4a,i.e. the swinging axle 29 of the boom lies in the vertical plane throughthe axis of the load arm 1; the chain 36 is adjusted according to itslength in such a manner that the yoke 25 is swung from its horizontalposition outwardly about a sharp angle of approximately 10 to 20 in ananti-clockwise direction, so that the swinging axle 29 which is disposedat a right angle to the counterbalance 25 is slightly inclined outwardlyat an equally sharp angle to the vertical from load arm 1. The weight ofthe boom and the running cable 17 keep the boom stable in this normalposition, the stability increasing during the final lifting or hoistingof the filled bucket. Additionally, the vane 54 is under the tensioningeffect of the spring 56 against the insert pins 55 inserted in therespective holes 52. An undesirable oscillation or a full lateralswinging of the boom is thus obviated without difliculty. Should thebucket 43 have reached the desired lift height, in which the bucket ison the level of the window sill of the window opening 2, then the bucket43 will be appropriately pulled in by means of a suitable hooked rod. Onthe other hand the booms 29, 30, 31, may also be swung outwardly fromtheir normal position. It will be readily apparent that when the centerof the bucket is swung outwardly over the extension of the cross axle24, which is possible when the resistance of the spring 56 is overcome,the counterbalance 25 (FIG. 2a) will tilt in clockwise direction aboutthe transverse axle 24, downwardly, until it bears on the striker 27 orthe buffer thereon of elastic material. In this tilted position, shownin dotted lines in FIG. 2a, the boom is stable and can only swing backunder the influence of spring 56. The installation is arranged in such amanner that in this side limit position of the booms swinging shown indotted lines in FIG. 4a, the counterbalance 25 is swung downwardly aboutan angle of 10 and 20 from the horizontal. From this limit swingingposition of the boom the bucket 43 may be set down on the building frameor it may be fetched into the building through the window opening 2.

As mentioned above the drive is constructed as an automatically stoppingworm gear drive. When larger loads are lifted, however, the danger ispresent that when the motor is stopped, the automatic brake action ofthe drive may be overcome by the free-hanging load. This is prevented bythe brake wheel 12 equipped with free-wheeling and the belt 14. Thedevice is constructed in such a manner, that the load, while beinglifted, acts between the wheel 12 and the motor shaft of the freewheeling device when the cable 17 travels in an opposite direction, thewheel 12 is coupled with the motor shaft and is braked by means of thetensioned belt 14. As long as the drive is connected this slip frictionwill be overcome without difiiculty when the drive is at a standstill.This friction sufiices, however, to maintain the cable absolutelystationary by it self-braking.

From the above it will be apparent that the described hoisting deviceforms a relatively compact unit which may be mounted practicallyanywhere; a separate mounting of the cable drum and its drive motor isnot necessary. The hoisting device may be easily transported. For thispurpose the boom is swung to the limit of its lateral position andsecured in such position, while the cable drum 16 is removed from thedrive housing and may be secured to a suitable holding bolt at the frame23 or at an adjacent load arm end, while the load arm 1 in one of thebooms, the winch bearing part and the part bearing the motor and thedrive may be disassembled. The dimensions of the hoisting device partsto be transported become relatively small. The extent of reach of theboom is considerably increased by the two-part load arm 1 and, as shownin FIG. 1, the load arm 1 while requiring a small amount of space,permits the bridging of relatively larger spaces between the boom andthe support locations.

I claim:

1. Window crane, comprising, in combination, a crane support means, ahorizontal load arm having an inner end and an outer end, said inner endbeing detachahly secured to said support means, a U-shaped frame membersecured with its base to the outer end of said load arm, an axle securedtransversely to the legs of said U-shaped member, a balance swingablymounted on said axle, a supporting bearing secured to said balance, atubular upwardly extending swinging axle mounted in said bearing, meansfor securing said swinging axle in a chosen position, an upper strut anda lower strut, each of said struts having one end secured to the upperand lower ends of said swinging axle, respectively, a first yokesecuring the other ends of said struts to one another, a second yokepivotally secured with its upper portion to said balance, a third yokesecured to said other end of the upper strut, each of said yoke having asheave secured thereto, an electric power drive secured to said supportmeans, a cable operable by said drive and extending through said sheavesand having a downwardly depending end for securing a load, first sensingmeans associated with said first yoke for cutting off power when theload is too high and second sensing means associated with said secondyoke for cutting off power to said power drive when the load is on theground.

2. Window crane according to claim 1, wherein said first sensing meanscomprises a switch secured to said first yoke, a two-arm angular memberhaving one arm pivoted to said first yoke and provided with a switchfinger cooperating with said switch, the other arm of said angularmember having a guide opening for said cable, a spring for biasing saidswitch finger against said switch, one end of said spring being securedto said one arm, the other end of said spring being secured to saidfirst yoke and means for connectin' said switch to said electrical powerdrive.

3. Apparatus according to claim 1, wherein said second sensing meanscomprises an electrical switch mounted on said balance, said balancehaving an aperture therethrough, the upper portion of said second yokebeing provided at its upper end with a switch finger adapted to extendthrough said aperture and cooperating with said switch and a spring forbiasing said upper end of said econd yoke and said striker element in adirection away from said switch, one end of said spring being secured tosaid balance, its other end being secured to the lower end of said yoke.

4. Window crane according to claim 3, wherein said upper portion of saidsecond yoke is provided with an upwardly extending striker forrestricting the swinging of said second yoke under the influence of thecables pull against the tensioning effect of said spring.

5. Apparatus according to claim 4, wherein said U-shaped frame isprovided with a base piece and an elastic buffer element for saidbalance secured to said base piece.

6. Window crane according to claim 5, wherein said means for securingthe crane in a chosen position, comprises a collar for said swingingaxle, struts for supporting said collar, a plurality of vanes, saidcollar having a plurality of holes therein, insert pins adapted forplacement in said holes and cooperating with said vanes for holding saidswinging axle.

References Cited UNITED STATES PATENTS 1,658,873 2/1928 Younkman 21281,720,714 7/1929 Bergesen 2128 2,529,193 11/1950 Renter 21239 2,544,5533/1951 Eakin 21246 3,024,918 3/1962 Cline 212-8 3,094,221 6/1963 Galuska212-39 FOREIGN PATENTS 1,308,202 12/1961 France.

EVON C. BLUNK, Primary Examiner.

H. C. HORNSBY, Assistant Examiner.

